Photonic Generation of Arbitrary Microwave Waveforms with Anti-Dispersion Transmission Capability.

We propose and demonstrate a photonic-assisted approach for generating arbitrary microwave waveforms based on a dual-polarization dual-parallel Mach-Zehnder modulator, offering significant advantages in terms of tunability of repetition rates and anti-dispersion capability. In order to generate diverse microwave waveforms, two sinusoidal radio frequency signals with distinct frequency relationships are applied to the dual-polarization dual-parallel Mach-Zehnder modulator. By adjusting the power of the applied sinusoidal radio frequency signal, the power ratio between these orthogonal polarized optical sidebands can be changed, and thereby desired radio frequency waveforms can be obtained after photoelectric conversion.

Improvement on stability of direct modulation laser with integrated active feedback by partial corrugated gratings.

Researchers have developed a uniform grating DFB with an integrated active optical feedback waveguide (UG-AFDFB) to enhance the modulation speed of direct modulation lasers (DMLs) while reducing costs based on identical active layer designations. However, this design has difficulties in obtaining high single mode yield (SMY) and low relative intensity noise (RIN) as a result of the strong optical feedback caused by the integrated active feedback waveguide (AFW) and the random phase of the facet phase. In this paper, a partial corrugated grating DFB with an integrated active optical feedback waveguide (PG-AFDFB) is proposed to address this issue.

Optical format interconversion nodes between OOK and QPSK enabled by a reconfigurable two-dimensional vector mover.

An optical format interconversion scheme between on-off keying (OOK) and quadrature phase shift keying (QPSK) is proposed and verified in this paper. The conversion system mainly consists of a coherent vector combiner and a reconfigurable two-dimensional (2D) vector mover. As a key element of the proposed conversion system, the 2D vector mover is implemented by a non-degenerate phase-sensitive amplifier (PSA).

Photoninduced charge redistribution of graphene determined by edge structures in the infrared region.

By using the ab initio density-functional theory method, we investigated the charge redistribution of monolayer graphene with ZigZag and/or ArmChair edges upon infrared excitation. The photoinduced charge redistribution is strongly dependent on edge types. The priority of electrons transfer has been revealed by charge density difference.